To reconstruct an erectile penis, an arteriovenous(AV) fistula was formed by anastomosing an artery and vein peripheral to a penis reconstructed using a free tissue flap with a vascular pedicle, so that erection could be achieved by compressing the root of the reconstructed penis to induce congestion.When making an AV fistula distal to a free flap, the blood steal phenomenon can lower blood flow to the flap tissue, resulting in flap necrosis. Safety therefore had to be clarified first. As grafting a free flap requires microvessel suturing, anastomotic thrombosis is likely, but AV fistula increases blood flow in the anastomotic region, so anastomotic thrombosis may be prevented. The purposes of the present study was to investigate these points.The study was conducted using adult dogs. Flap congestion was observed and venous pressure and blood flow in the femoral artery in the flap and flap blood flow were measured and compared with or without AV fistula after lifting an island flap with
… More the saphenous artery and vein of the lower thigh as vascular pedicles.Blood flow of the femoral artery, which served as the feeding vessel of the flap, decreased significantly after lifting the flap. Macroscopically, arterial pulsation and vascular wall tension decreased. When an AV fistula was made peripheral to the flap, blood flow increased by about 45-fold, and the increased blood flow of the femoral artery remained high during the second week postoperatively. Furthermore, blood flow to the flap tissue decreased by about 50% with the femoral AV fistula, but returned to preoperative levels by the second week, and no flap necrosis was seen.These findings show that a decrease of about 50% in blood flow to the skin does not cause flap necrosis and supports the safety of grafting a flap with an AV fistula. AV fistula made with a free flap is extremely useful in preventing anastomotic thrombosis due to the marked increase in blood flow in the anastomotic region.In future, we plan to clarify the long-term pathological changes and patency of veins in this AV fistula model and clarify damage to flap tissue caused by compressing the flap base to induce congestion. Less